CN221766376U - Thin-wall insulating fire-resistant flexible cable for rail transit - Google Patents

Abstract

The utility model relates to a thin-walled insulated fire-resistant flexible cable for rail transit, belonging to the technical field of cables. The technical scheme is: a plurality of tinned copper conductors (1) are bundled and twisted together, and then wrapped with a calcined muscovite fire-resistant layer (2); the calcined muscovite fire-resistant layer (2) is wrapped with a low-smoke, halogen-free, flame-retardant, cross-linked polyolefin insulation layer (3) to form a wire core; a plurality of wire cores are twisted together to form a cable core, and a flame-retardant filler (7) is arranged inside the cable core; a reinforced fire-resistant mica layer (4), a tinned braided shielding layer (5) and a cross-linked low-smoke, halogen-free, flame-retardant polyolefin sheath layer (6) are arranged outside the cable core in sequence. The utility model improves the flexibility of the cable, reduces the breakage of the cable conductor, ensures that the circuit of the cable is complete when the flame propagates, ensures that the cable has high strength, excellent flame retardant performance, and low temperature resistance, improves the comprehensive protection performance of the cable such as wear resistance, corrosion resistance, and fire resistance, improves the voltage level of the cable, improves the safety protection of the cable, and improves the service life of the cable.

Description

A thin-wall insulated fire-resistant flexible cable for rail transit

Technical Field

The utility model relates to a thin-wall insulated fire-resistant soft cable for rail transportation, belonging to the technical field of cables.

Background Art

Rail transit refers to transportation vehicles that run on specific tracks. Rail transit can be divided into subways, trams, light rails and high-speed rails. In recent years, with the continuous development of social economy, the national rail transit has shown leapfrog development, and the demand for low-smoke halogen-free flame-retardant rail transit cables has also increased significantly. In the face of the ever-increasing rail transit control equipment, higher requirements are placed on cables. Ordinary low-smoke halogen-free flame-retardant rail transit cables are not fire-resistant, have poor flexibility, are easy to age, have a short lifespan, and have low mechanical properties. They can no longer fully meet the technical requirements under specific conditions.

Utility Model Content

The utility model aims to provide a thin-wall insulated fire-resistant flexible cable for rail transit, which is achieved by twisting soft tinned copper conductors and wrapping the tinned copper conductors with a calcined muscovite fire-resistant layer, adopting a high-strength low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer and a cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer, and has the characteristics of excellent electrical properties, good flexibility, aging resistance, good comprehensive protection performance, long service life, etc., and solves the problems existing in the background technology.

The technical solution of the utility model is:

A thin-wall insulated fire-resistant flexible cable for rail transit, comprising a tinned copper conductor, a calcined muscovite fire-resistant layer, a low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer, a flame-retardant filler, a reinforced fire-resistant mica layer, a tinned braided shielding layer and a cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer. A plurality of tinned copper conductor bundles are twisted together and then wrapped with a calcined muscovite fire-resistant layer. The calcined muscovite fire-resistant layer is extruded with a low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer to form a wire core. Multiple wire cores are twisted together to form a cable core. A flame-retardant filler is provided in the cable core. A reinforced fire-resistant mica layer, a tinned braided shielding layer and a cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer are arranged in sequence outside the cable core.

The stranding direction of the plurality of tinned copper conductors is left-handed, and the pitch is 8-14 times of the stranding diameter.

The calcined muscovite refractory layer and the reinforced refractory mica layer are both made of calcined muscovite with a thickness of 0.12 mm, and are double-layered with 50% overlap.

The thickness of the low-smoke, halogen-free, flame-retardant, cross-linked polyolefin insulation layer is 0.4 mm.

The tinned braided shielding layer is woven from tinned copper wires, the single wire of the tinned copper wires is 0.1-0.15 mm, the braiding machine is a 16-spindle braiding machine, the braiding density is 80%, and the braiding angle is 15°-35°.

The number of the wire cores is three, and the wire cores are arranged in a finished product shape.

The tinned copper conductor is a Class 5 tinned soft copper conductor that complies with the EN50306-2 standard.

The beneficial effects of the utility model are:

1. The use of tinned copper conductor improves the flexibility of the cable, reduces cable conductor breakage, and increases the service life of the cable;

2. The calcined muscovite refractory layer is double-layered and wrapped with 50% overlap to ensure the integrity of the cable circuit when the flame spreads; the double-layered refractory mica layer is strengthened and wrapped with 50% overlap to enhance the fire resistance of the cable;

3. The low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer and the cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer ensure that the cable has high strength, excellent flame retardant properties, and low temperature resistance, improves the cable's comprehensive protection properties such as wear resistance and corrosion resistance, improves the cable's voltage level, improves the cable's safety protection, and increases the cable's service life.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic diagram of the structure of the utility model;

In the figure: tinned copper conductor 1, calcined muscovite fire-resistant layer 2, low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer 3, reinforced fire-resistant mica layer 4, tinned braided shielding layer 5, cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer 6, flame-retardant filler 7.

DETAILED DESCRIPTION

The present invention will be further described below through examples in conjunction with the accompanying drawings.

A thin-wall insulated fire-resistant flexible cable for rail transit, comprising a tinned copper conductor 1, a calcined muscovite fire-resistant layer 2, a low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer 3, a flame-retardant filler 7, a reinforced fire-resistant mica layer 4, a tinned braided shielding layer 5 and a cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer 6; a plurality of tinned copper conductors 1 are twisted together and wrapped with a calcined muscovite fire-resistant layer 2, a low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer 3 is extruded outside the calcined muscovite fire-resistant layer 2 to form a wire core, a plurality of wire cores are twisted to form a cable core, and a flame-retardant filler 7 is arranged inside the cable core; a reinforced fire-resistant mica layer 4, a tinned braided shielding layer 5 and a cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer 6 are arranged in sequence outside the cable core.

The utility model is formed by twisting 5 types of soft tinned copper conductors that meet the EN50306-2 standard. The specific process is to twist a plurality of tinned copper conductors 1 together in a concentric twisting manner, the direction is left-handed, and the pitch is 8 to 14 times the bundle diameter. Compared with traditional soft conductors, the twisting pitch is small, the cable conductor is soft, and it is not easy to break the wire, which is convenient for installation in a small space and increases the service life of the cable.

The plurality of tinned copper conductors are twisted together into a bundle and then wrapped with 0.12 mm thick calcined muscovite in two layers with 50% overlap. The wrapping is smooth and the overlap rate is controlled as required to ensure the wrapping coverage stability and to ensure that a stable and uniform protective shell is formed after external flame combustion to achieve circuit integrity.

The calcined muscovite refractory layer 2 is extruded with a layer of low-smoke, halogen-free, flame-retardant, cross-linked polyolefin insulation layer 3, the thickness of which is controlled at a thin insulation level of 0.4 mm, and the extrusion concentricity is controlled at more than 75%, ensuring that the cable passes the 0.6/1kV cable product standard finished product withstand voltage test. On the basis of ensuring good electrical insulation performance, the insulation's oil resistance, flame retardancy, low temperature resistance, and mechanical strength are enhanced, and the cross-linking not only maintains the cable's softness but also improves and improves the insulation's aging resistance.

The cable core is wrapped with a reinforced fire-resistant mica layer 4 before braiding, namely a double layer of 0.12 mm calcined muscovite with 50% overlap, so as to enhance the fire-resistant performance.

The tinned braided shielding layer 5 is a tinned copper wire braided on the surface of multiple wire cores after being cabled. The diameter of the braided single wire is related to the diameter of the wire core. The braided single wire is 0.1-0.15 mm, the braiding machine uses a 16-spindle braiding machine, the braiding density is 80%, and the braiding angle is 15°-35°. The tinned braided shielding layer reduces the electromagnetic interference of control signals and strong electricity, stabilizes the control line, and maintains the softness of the cable for easy bending.

The cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer 6 adopts the sheath material of Solvay Pandena, which has good mechanical properties and comprehensive protection performance. The utility model cable is mostly used for wiring in locomotive compartment control cabinets and compartment boxes, and will encounter various harsh use environments. The sheath material has excellent oil resistance, acid and alkali resistance, UV resistance, wear resistance, cold resistance, high strength, toughness and aging resistance, and has excellent long-term aging performance, ensuring the cable has a service life of 30 years.

The utility model not only maintains the characteristics of small cable size, small space occupation and easy installation, but also provides continuous power supply when rail transit encounters fire, ensuring basic lighting and safe braking of various safety door control systems. This is an important electrical safety technical measure and an effective measure to ensure the normal operation of key electrical systems. It not only buys precious time for evacuating passengers, but also can maximize the safety of the people and public property within a certain range.

The utility model is composed of a tinned copper conductor 1, a calcined muscovite refractory layer 2, a low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer 3, a flame-retardant filler 7, a reinforced refractory mica layer 4, a tinned braided shielding layer 5 and a cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer 6. Each part has a compact structure and a strict production process control to ensure that it is suitable for installation and use in a narrow space of rail transit vehicles. The conductor of the cable adopts Class 5 tinned soft body to ensure that the conductor resistance meets the requirements, the conductor twisting pitch is adjusted to be small enough, and the twisting is twisted in a regular arrangement to ensure that the outer diameter of the conductor is stable and round. The general conductor specification range is ^0.5mm2 to ^4mm2 . The tinned copper conductor is wrapped with 0.12mm thick calcined muscovite, and the two layers are wrapped in a 50% overlap manner. The calcined muscovite refractory layer can ensure that a layer of inorganic protective shell is formed when a high-temperature flame occurs. Even if the outer layer of combustibles or the surrounding combustibles burn and catch fire, the power supply of the line can still be kept intact, and the control switch of the relevant line can be controlled and the normal safety lighting can be achieved. The low-smoke, halogen-free, flame-retardant, cross-linked polyolefin insulation layer with a higher insulation grade is used. To ensure the flame-retardant performance of the cable, its oxygen index should be not less than 29. Since the insulation is thin and generally controlled to 0.4mm, in order to ensure its mechanical properties, the insulation layer needs to be irradiated, and the insulation strength after irradiation cross-linking is not less than 25N/ ^mm2 . Flame-retardant filler 7 is provided in the cable core to enhance the flame-retardant effect of the cable and delay the spread of flames. The cable core is wrapped with 0.12mm calcined muscovite, which protects the insulating core inside and enhances the fireproof performance. The tinned braided shielding layer reduces the broken wires of the cable conductor, and the braided conductor surface is flat. After stripping the sheath, it is not loose, which is convenient for crimping with the terminal and connecting with the cable terminal, and is convenient for the installation and use of the cable. The cross-linked low-smoke, halogen-free, flame-retardant polyolefin sheath layer is used. After cross-linking, the strength is improved. It not only has better mechanical properties such as wear resistance and low temperature resistance, but also has comprehensive protective properties such as oil resistance and corrosion resistance, which improves the safety protection of the cable and increases the service life of the cable.

Advantages of the utility model:

1. Use tinned soft copper wire to twist 5 types of conductors, which improves the flexibility of the cable, reduces the breakage of the cable conductor, and increases the service life of the cable;

2. The calcined muscovite fire-resistant layer is wrapped with double layers of 50% overlap to ensure the integrity of the cable circuit when the flame spreads; before braiding, the cable core is wrapped with double layers of 0.12mm calcined muscovite with 50% overlap to enhance the fire resistance of the cable;

3. The design of irradiated low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer and cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer ensures that the cable has high strength, excellent flame retardant performance, low temperature resistance, improved wear resistance, corrosion resistance and other comprehensive protection performance of the cable, improved the safety protection of the cable, and increased the service life of the cable;

4. The cable has a low-smoke, halogen-free, flame-retardant, cross-linked polyolefin insulation layer with a thickness of 0.4mm, and a concentricity of more than 75%. The rated voltage of the cable is increased from the original standard 300/500V to 0.6/1kV, and the finished cable withstand voltage test is 3.5kV/5 minutes. The cable withstand voltage is higher than the standard EN50306 requirements, and the voltage level is increased, so it can work normally under higher system voltage.

Claims (5)

1. The utility model provides a thin wall insulation fire-resistant flexible cable for track traffic which characterized in that: the cable comprises a tin-plated copper conductor (1), a calcined muscovite fire-resistant layer (2), a low-smoke halogen-free flame-retardant crosslinked polyolefin insulating layer (3), flame-retardant fillers (7), a reinforced flame-resistant mica layer (4), a tin-plated woven shielding layer (5) and a crosslinked low-smoke halogen-free flame-retardant polyolefin sheath layer (6), wherein a plurality of tin-plated copper conductors (1) are twisted together and then are wrapped and calcined around the calcined muscovite fire-resistant layer (2), the calcined muscovite fire-resistant layer (2) is wrapped by the low-smoke halogen-free flame-retardant crosslinked polyolefin insulating layer (3) in an extrusion manner to form a cable core, a plurality of cable cores are twisted to form a cable core, and the flame-retardant fillers (7) are arranged in the cable core; the cable core is externally provided with a reinforced fireproof mica layer (4), a tinning braided shielding layer (5) and a crosslinked low-smoke halogen-free flame-retardant polyolefin sheath layer (6) in sequence.

2. A thin-walled insulated flexible power cable for rail transit as defined in claim 1, wherein: the direction of the beam twisting of the plurality of tin-plated copper conductors (1) is left, and the pitch is 8-14 times of the diameter of the beam twisting.

3. A thin-walled insulated flexible power cable for rail transit as defined in claim 1 or 2, wherein: the calcined muscovite refractory layer (2) and the reinforced refractory mica layer (4) are both calcined muscovite with the thickness of 0.12 mm.

4. A thin-walled insulated flexible power cable for rail transit as defined in claim 1 or 2, wherein: the thickness of the low-smoke halogen-free flame-retardant crosslinked polyolefin insulating layer (3) is 0.4mm.

5. A thin-walled insulated flexible power cable for rail transit as defined in claim 1 or 2, wherein: the tinning braided shielding layer (5) is formed by braiding tinned copper wires, wherein monofilaments of the tinned copper wires are 0.1-0.15 mm, the braiding density is 80%, and the braiding angle is 15-35 degrees.